Blowout preventer convenient to install and fix and provided with protection structure

The invention discloses a blowout preventer convenient to mount and fix and provided with a protection structure, four limiting plate mechanisms are symmetrically arranged at the top of a mounting plate, protection plates are slidably connected to the inner sides of the limiting plate mechanisms, the bottoms of the protection plates penetrate through the mounting plate, a mounting box is arranged on one sides of the limiting plate mechanisms, and a first rotating handle mechanism is mounted on the outer side of the mounting box; one end of the first rotating handle mechanism is connected with a first threaded rod arranged in the mounting box, the outer side of the first threaded rod is connected with a threaded sleeve, a moving opening matched with the threaded sleeve is formed in the side, close to the limiting plate mechanism, of the mounting box, and through grooves matched with the threaded sleeve are formed in the upper side and the lower side of the protection plate. According to the blowout preventer c